A. Field of the Invention
The present invention relates most generally to the field of heating systems and microwave ovens and more particularly to an adjusting and tuning arrangement provided within a microwave oven to accomplish desired energy distributions within the oven.
B. Description of the Prior Art
In various applications of electromagnetic heating systems or microwave ovens, it is desirable to control the energy distribution within the heating cavity either in a nonuniform or uniform pattern to different areas of the cavity.
Such control is desirable in applications such as institutional feeding plans whereby a complete meal is elevated to serving temperatures in an efficient manner including items on a single tray which are to be served at different temperatures.
Systems and feeding plans of this variety are discussed and described in U.S. Pat. Nos. 3,854,021 which issued to Donald G. Moore, et al. on Dec. 10, 1974 and 3,854,022 which issued to Donald G. Moore on Dec. 10, 1974, which are hereby incorporated by reference for all purposes. The oven system referred to previously includes such energy control distribution arrangements as an energy shield designed or arranged to interfit with elements of the tray to shield certain items on the tray from being heated, such as ice cream or milk. A sensing element carried by the tray absorbs microwave energy along with certain food items on the tray and automatically controls the duration of the heating cycle in accordance with the requirements of the food items on the tray. The sensor location and energy shield both provide some measure of control of the energy distribution of the system.
However, further control of the energy distribution pattern is desirable to achieve various senergy distributions in various areas of the cavity or the tray to properly control distribution between the sensor assembly and load items depending upon load size, arrangement and characteristics of the oven. It would also be desirable to control the energy balance between various load items on the tray.